Does multi-port operation of a data center switch exacerbate CE exceedances?

Simultaneous operation of multiple ports on a data center switch increases the risk of conducted emissions exceeding standards due to the increased total power supply and the superposition of common-mode currents on multiple signal lines. Actual measurements show that under full load, the conducted interference at the power supply ports of a 24-port switch increases by 6-8 dB in the 150kHz-1MHz band and by 4-6 dB in the 1MHz-10MHz band compared to single-port operation. Countermeasures: Design filters based on full power requirements; the inductor saturation current must be greater than 1.3 times the maximum load current; select the CMZ7060A-701T (rated current 10A) from Etymotic to meet the requirements of a 48-port PoE++ model; use independent ferrite bead filters for each signal port to avoid sharing; ensure the power module has a margin of >30%. Actual measurements show that the fully configured model passes Class B testing with a margin of >4 dB.